$7-15$a

A $1/3-$hp$,3-$phase induction motor is rated at $120$ V phase voltage.$$With $40$V phase voltage applied, and the rotor locked, the measured torque and current are $0\mathrm{.}4$ ft$-$lb and $2\mathrm{.}65$ A respectively.$$If rated voltage is applied to the motor, what will be the starting torque?